1. Field of the Invention
The present invention relates to an assist handle for a vehicle and a method of assembling the assist grip handle to a vehicle by a snap-in process.
2. Background Art
Assist grip handles are provided in cars, trucks, and sport utility vehicles to assist occupants as they enter and exit a vehicle. Assist grip handles may be static or dynamic. Dynamic handles are movable between an extended position and a retracted position. A wide variety of assist grip handle designs are available. Currently available assist grip handles may be attached to the roof through the head liner or may be attached to one of the roof support pillars that are known as the A, B, or C pillars either directly or through a trim piece. The A pillar is the roof support pillar located between the windshield and the first row seat window. The B pillar is the roof support pillar between the front and rear doors or in a coupe as the pillar located behind the doors of the vehicle. The C pillar is the roof support pillar located between the rear door and the back light of the vehicle. Assist grip handles are generally located near door openings so that they may be easily grasped by a passenger as they enter or exit the vehicle.
Prior art assist grip handles as disclosed in U.S. Pat. No. 5,259,089 and Offenlegungsschrift DE 3,607,744 A1 are normally secured by conventional fasteners, to a hole formed in a sheet metal part. Assist grip handles have two ends and require at least two fasteners that locate and secure the two ends of the assist grip handle to the mounting surface. This requires a substantial amount of time in the final assembly process and adds to the cost of assembly. Assist grip handles must be able to withstand more than 1,400 Newtons of force applied to the handle without becoming dislodged from the mounting surface. Previously, the only way known to the inventors to provide an assist grip handle robust enough to withstand such pressure was to secure the assist grip handle with permanent fasteners that must be assembled to the vehicle in the final assembly process. The maximum insertion force for assembling such handles to a vehicle may not exceed 68.6 Newtons of force per palm.
Other approaches suggested by the prior art include complex clip arrangements, such as the apparatus disclosed in U.S. Pat. Nos. 5,662,375; 4,912,808; and 4,404,709. These devices are multi-part assemblies that would be difficult to consistently manufacture and assemble in such a way that they would meet the proposed insertion and extraction force requirements for assist grip handles.
The present invention is directed to overcoming the above problem, as will be summarized below.
According to one aspect of the present invention, a handle assembly for assisting passengers in entering and exiting a vehicle is provided that comprises a handle grip having two ends with each end having a retainer. Two base units with one base unit being provided for each end of the handle grip are provided that have at least one snap element that is adapted to be press fit into an opening formed in a structural part of the vehicle. These snap elements are configured to be retained in the opening against a removal force that is substantially greater than the force required to press fit the snap element in the opening. The base element defines a receptacle for a fastener that secures the retainer of the handle to the base unit.
According to another aspect of the invention, a method of assembling an assist grip handle to a vehicle is provided that comprises forming at least two holes in a structural body panel. An assist grip handle is provided that has a pair of opposite ends. A pair of base units are provided on each of the opposite ends of the assist grip handle each of which includes two projections having detents. The assist grip handle is assembled to the base units off of the assembly line while the step of assembling the base units to the vehicle is accomplished by asserting each of the projections into one of the holes in the body panel. The detents are compressed as the projections are inserted into the holes and then expanded after the projections are sufficiently inserted into the holes. The assist grip handle is retained by the detents against forces applied to the assist grip handle after installation.
According to another aspect of the invention, the base unit may have two molded snap elements including a primary snap element and an auxiliary snap element that is smaller than the primary snap element. Each snap element is a protrusion having a longitudinal axis having at least one detent that is movable toward and away from the longitudinal access. The detent moves toward the access when the snap element is inserted in the opening in the structural part of the vehicle and moves away from the access after it is inserted. The detent may also be referred to as a tang having an entrant cam surface that comprises the detent as the projection is initially inserted in the hole and reentrant cam surface that is received in the hole and resists removal of the projection. A pair of covers are also provided to enclose the retainers of one of the fasteners and also partially encloses one of the base units.
Other aspects of the method of the invention include forming two large diameter holes and two small diameter holes in the vehicle for receiving two primary projections and two auxiliary projections formed on the molded base units. The detents provided on the base units comprise molded cantilevered tangs on oppositely oriented sides of the projections that have entrant cam surfaces that compress the detent as the projection is initially inserted in the hole and a reentrant cam surfaces over which the hole passes that resist removal of the projections. The projections may be injection molded as part of the base units in one piece. According to the method, the assist grip handle end may be assembled to the base units by a fastener before the base units are assembled to the vehicle.
These and other aspects of the invention will be understood by one of ordinary skill in the art in view of the attached drawings and following detailed description of the preferred embodiments.